| 요약2 |
In this study, the mechanical properties of ready-mixed concrete with recycled coarse aggregate(RCA) were discussed. The mixing types were composed of twelve series based on specified compressive strength(i.e 21, 27, and 40MPa) and replacement ratio of recycled coarse aggregates(i.e 0, 30, 60 and 100%). Recycled coarse aggregate utilized in the study consists of 71.43% high quality recycled coarse aggregate, 28.57% low quality recycled coarse aggregate by weight. The properties of the fresh concrete were measured by means of slump and air content according to elapsed time. The strength properties of the hardened concrete were measured by means of compressive strength, splitting strength and modulus of rupture. Also test result were compared with existing domestic Codes(KBC2005 and KCI2007). Test result indicated that the replacement ratio of recycled coarse aggregate had little effect on fresh properties, such as slump and air content, of RCA concrete. Compressive strength, splitting strength and modulus of rupture of concrete is little affected by the replacement ratio of recycled coarse aggregate. And elastic modulus, splitting strength and modulus of rupture show relatively low values compared with relevant provisions in KBC2005 and KCI2007. Therefore, some design coefficients or recommendations in existing design code for natural aggregate concrete need to be amended for recycled aggregate concrete. |